This application is a continuation-in-part of U.S. Provisional Patent Application No. 60/411,136, filed on Sep. 16, 2002, now abandoned.
Optical connections to circuit boards in the past have typically been limited to a single optical fiber at a time. Such connections have typically involved the use of an optical transmitter or detector placed within a cylindrical metal enclosure with a transparent top (i.e., a “TO can ”) and soldered to a circuit board.
Since TO cans do not inherently have provisions for cable attachment, an annular cable supporting structure is typically attached to the circuit board that also supports the TO can. An example of a TO can is shown in FIG. 1. Typically, the annular structure is placed over the TO can with a central hole of the structure disposed over the transparent top of the TO can to bring the optical fiber of the waveguide into alignment with the optical device within the TO can. To secure the waveguide to the board, a female thread on the waveguide engages a male thread disposed around the hole in the annular structure.
While the use of waveguides with TO cans has been successful, it is also difficult to use and time consuming to assemble. Often the optical device within the TO can is not precisely aligned with the outside of the TO can. As a consequence, alignment is typically achieved by trial and error. Often the optical device is activated and the waveguide is moved around a predetermined path over the TO can to identify the location of greatest signal transfer. The supporting structure may then be secured to the circuit board in that location.
In addition, TO cans may require complex lensing systems to accurately transfer optical signals to optical fibers. In contrast, by flip chipping optical IC's to substrate, where the optical signals are emitted from the same surface as the electrical contacts, optical fibers can be placed closer to the source of light. This in turn may reduce the need for lensing systems.
However, as many optical devices are placed on a substrate, cross talk of optical signals may require further lensing to ensure high signal integrity, Where many connectors are required, the most of assembly becomes prohibitive. Accordingly, a need exists for a reliable method of couple more than 1 optical signal to respective optical fibers, while maintaining signal integrity, reducing the cost, and reducing the complexity of the coupling system.